Using Serviceguard Extension for RAC, 5th Edition, June 2007

Serviceguard Configuration for Oracle 10g RAC
Network Planning for Cluster Communication
Chapter 2 47
Network Planning for Cluster Communication
The network for cluster communication is used for private internal
cluster communications. Although one network adapter per node is
sufficient for the private network, it is recommended that a minimum of
two network adapters for each network to be used for higher availability.
The following are the major categories of inter-cluster traffic in an
SGeRAC environment:
• Serviceguard HeartBeat (SG-HB): Serviceguard heartbeat and
communications traffic. Supported over single or multiple subnet
networks.
• Cluster Synchronization Services Heartbeat (CSS-HB): CSS
heartbeat traffic and communications traffic for Oracle Clusterware.
CSS-HB uses a single logical connection over a single subnet
network.
• RAC Interconnect (RAC-IC): RAC instance peer to peer traffic
and communications for Global Cache Service (GCS) and Global
Enqueue Service (GES), formally Cache Fusion (CF) and Distributed
Lock Manager (DLM). Network HA is provided by the HP-UX
platform (Serviceguard or Auto Port Aggregation (APA)).
• Automatic Storage Management Interconnect (ASM-IC) (only
when using ASM, Automatic Storage Management): ASM instance
peer to peer traffic. When it exists, ASM-IC should be on the same
network as CSS-HB. Network HA is required either through
Serviceguard failover or APA bonding.
• Global Atomic Broadcast/Link Level Traffic (GAB/LLT) (only
when using CFS/CVM): Symantec cluster heartbeat and
communications traffic. GAB/LLT communicates over link level
protocol (DLPI) and supported over Serviceguard heartbeat subnet
networks, including primary and standby links.
The most common network configurations is to have all interconnect
traffic for cluster communications to go on a single heartbeat network
that is redundant so that Serviceguard monitors the network and
resolves interconnect failures by cluster reconfiguration.
• The following are situations when it is not possible to place all
interconnect traffic on a single network: